fat: Fix possible null deref in fat_cache_add()
fat: Fix possible null deref in fat_cache_add()

Reported-by: <dcb1749dd31d79a0727490bff30ada59f99408a7@mail.ru>
Signed-off-by: OGAWA Hirofumi <1dd685eef08048be95744a1b104ca593a93cc914@mail.parknet.co.jp>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs